Finally got my Tiny G connected last night to my home built CNC router (modified JGRO build). Configuration was easy and it works great. I also have a Grbl Shield that I was using, but, swapped it out for the Tiny G because it seems to be more robust. One notable thing is that the Tiny G has the option to 'un power' the motors when they're not in use, so, it tends to run much cooler when idling.
I posted under Hardware support, but, this is really just a success story.